Mobile mine roof support



Oct. 28, 1969 w. WILKENLOH ETA!- 3,474,628

MOBILE MINE ROOF SUPPORT Filed Sept. 16, I968 2 Sheets-Sheet l lawn/0r.

Oct. 28, 1969 w. WILKENLOH ETAL 3,474,628

MOBILE MINE ROOF SUPPORT 2 Sheets-Sheet 2 Filed Sept. 16, 1968 In ven far l/Ml/Ebfl Milka/$ 1,!

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United States Patent 3,474,628 MOBILE MINE ROOF SUPPORT Wilhelm Wilkenloh, Duisburg-Wanheim, and Manfred Koppers, Duisburg-Hamborn, Germany, assignors to Reinstahl Wanheim GmbH, Duisburg- Wanheim, Germany Filed Sept. 16, 1968, Ser. No. 759,999 Claims priority, application Germany, Sept. 22, 1967, 1,583,115 Int. Cl. E21d 23/20, 15/44 US. C]. 61-45 12 Claims ABSTRACT OF THE DISCLOSURE A mobile mine roof support wherein the pit props are arranged in transversely aligned pairs located one behind the other. Each pair of props is articulately supported by a sole plate and the front plate is pivotally connected to the ends of arcuate carriers which are movable are movable back and forth with reference to a rigid frame structure about an axis which is parallel to the direction of movement of the mine roof support toward the mine face in an underground excavation. The front sole plate is free to swing with reference to the carriers about a hori zontal axis which is normal to the direction of movement of the mine roof support. The rear sole plate is connected to the frame structure by a universal joint and each prop is movable up and down in a sleeve provided therefor on the frame structure. The carriers for the front sole plate are coupled to the frame structure by four fluid-operated or spring-loaded cylinder and piston units which bias the front sole plate to a neutral position.

BACKGROUND OF THE INVENTION The present invention relates to improvements in mobile mine roof supports. More particularly, the invention relates to improvements in mine roof supports which comprise several extensible and contractible pit props which carry one or more roof-engaging caps and are mounted on sole plates which engage the floor of an underground excavation.

It is already known to provide a mobile mine roof support with a rigid frame which is coupled to the props. The props are arranged in groups and the props of each group are connected to each other. Furthermore, the lower portions of props in each group are supported by a sole plate. As a rule, the mine roof support includes four props which are disposed at the corners of a rectangle. The sole plates in such mine roof supports should perform several important functions in that they should contribute significantly to the safety, life expectancy and versatility of the apparatus. An important requirement is to mount the sole plates in such a way that they can readily follow the outline of an uneven mine floor so as to prevent excessive stressing and eventual breakage or deformation of the apparatus when the props are extended so that their caps engage the mine roof. On the other hand, the connections between the sole plates and the rigid frame structure should not be too loose because a loosely mounted sole plate permits excessive swinging or swaying of props when the caps are disengaged from the mine roof and the apparatus is in the process of being advanced toward the mine face. In many presently known mine roof supports, the props are slidable in sleeves carried by the frame structure and are coupled to their sole plates by universal joints. Liners of rubber are inserted between the sleeves and the adjoining portions of mine props. A drawback of such apparatus is that the liners harden in an underground excavation after a short period of use and also that the restoring force produced I? ice by elastic liners is rather weak so that such liners cannot maintain the props and the sole plates in requisite optimum position when the apparatus is caused to walk toward the mine face.

It is also known to employ in a mine roof support a plate-like connector of limited elasticity which couples the sole plates to each other in such a way that the sole plates can move up and down but not in other direction or directions. The lower end portions of the props are mounted on the sole plates by means of ball joints. Such construction reduces the tendency of props to swing during movement of the apparatus toward the mine face; however, the ability of sole plates to follow the outline of a rough and sloping mine floor is reduced to such an extent that the apparatus is often subjected to excessive stresses when the sole plates are unable to move into full surfaceto-surface contact with the mine floor.

SUMMARY OF THE INVENTION It is an object of our present invention to provide a simple, rugged, reliable and long-lasting mobile mine roof support wherein the sole plates are movable with reference to the frame structure in several directions so that they can readily follow the outline of an uneven mine floor and wherein the props are mounted and confined in such a way that they cannot sway excessively when the caps are moved away from the mine roof and the apparatus is in the process of moving toward the mine face.

Another object of the invention i to provide a mobile mine roof support wherein at least one of the sole plates, particularly the front sole plate, is mounted in a novel and improved way which enables such sole plate to move in all or nearly all directions with reference to the frame structure.

A further object of the invention is to provide a mine roof support wherein the sole plates are connected to the rigid frame structure in a novel and improved way.

An additional object of the invention is to provide a novel connecting assembly between the sole plates and the rigid frame structure of a mobile mine roof support.

The invention is embodied in a mine roof support (also known as a walking mine roof support) which is movable in an underground excavation along the mine floor and toward the mine face. The mine roof support comprises a plurality of substantially upright pit prop means located one behind the other as considered in the direction of movement toward the mine face and each preferably comprising a pair of transversely aligned mine props located at the opposite sides of an elongated rigid frame structure which preferably mounts an extensible cylinder and piston assembly serving to effect forward movement of the mine roof supports, a sole plate articulately connected with the lower end portions of each pair of transversely aligned props, means provided on the frame structure to guide the pit props for movement up and down, and a plurality of connector means securing the sole plates to the frame structure. At least one of these connector means (preferably the connector means for the front sole plate) comprises rigid carrier means coupled with the respective sole plate at the opposite sides of the frame structure, and guide means preferably including arcuate way provided on the frame structure for the carrier means to permit at least some movement of the carrier means with reference to the frame structure, preferably a back-and-forth movement about an axis which is parallel to the direction of movement of the mine roof support toward the mine face. The one connector means preferably further comprises one or more elastic coupling units which connect the carrier means with the frame structure, and each such coupling unit may comprise a fluid-operated or a spring-loaded cylinder and piston assembly which tends to bias the carrier means and the respective sole plate to a predetermined position with reference to the frame structure.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved mine roof support itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of a specific embodiment with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevational view of a mobile mine roof support which embodies the invention;

FIG. 2 is a fragmentary front elevational view of the mine roof support as seen from the right-hand side of FIG. 1;

FIG. 3 is a fragmentary rear elevational view of the mine roof support as seen from the left-hand side of FIG. 1, with certain parts shown in a transverse vertical sectional view; and

FIG. 4 is a top plan view of the mine roof support, with the roof-engaging caps removed.

DESCRIPTION OF THE PREFERRED EMBODIMENT The mobile mine roof support of FIGS. 1 to 4 comprise two pairs of transversely aligned extensible and contractible hydraulic pit props including a front pair or group of props 2a and a rear pair or group of props 2!). Each front prop 2a cooperates with one of the rear props 2b to carry an elongated roof-supporting cap 1. The two groups of props are coupled to a rigid supporting frame including a centrally located longitudinally extending elongated frame member 3, two pairs of arms 22 which are fixed to the frame member 3 and extend upwardly therefrom in the space between the front and rear groups of props, and plocks 24 located between the upper portions of such pairs of arms. The mine roof support further comprises two articulately mounted sole plates 5, 6 which are respectively coupled to the lower end portions of the rear and front props 2b, 2a. A shifting cylinder 16 is mounted in the interior of the frame member 3 and has a piston rod 16a which carries at its front end a coupling element 16b adapted to be coupled to a customary conveyor in front of the mine face and serving to convey coal or other material which is removed from the mine face laterally and on to a further conveyor which transports the material from the underground excavation. Briefly stated, the operation of the mine roof support is such that when the drill removes material from the mine face which is located in front of the apparatus, i.e., to the right of the caps 1 as viewed in FIG. 1, the props 2a, 2b are extended so that the sole plates 5, 6 bear against the mine floor and the caps I bear against the mine roof to prevent cave-in during removal of material. When the apparatus is to be shifted toward the mine face, the piston rod 16a is expelled forwardly (to the right, as viewed in FIG. 1) and thereby advances the conveyor toward the mine face. In the next step, the mine props 2a, 2b are shortened, i.e., the caps 1 move downwardly and away from the mine roof, and the cylinder 16 then receives hydraulic fluid in a sense to retract the piston rod 16a. However, since the weight of the conveyor is greater than that of the mine roof support, the cylinder 16 travels to the right, as viewed in FIG. 1, and causes the sole plates 5, 6 to slide along the mine floor and toward the mine face. The props 2a, 2b are thereupon extended so that the caps 1 reengage the mine roof and the removal of material from the mine face can begin anew.

One of several features of our present invention resides in novel mounting of the front props 2a and of the front sole plate 6. This sole plate is articulately coupled to the ends of two arcuate (substantially inverted U-shaped) carriers by way of stiffening brackets 23 which connect the end portions of the carriers 9 and pivot pins 12 which are journalled in such brackets. Thus, the sole plate 6 can turn about a transverse horizontal axis which is common to the two pivot pins 12. The median portions of carriers 9 (which are rigidly secured to each other by the brackets 23) are slidable in guide means here shown as channels or ways 13, 14 provided therefor on the aforementioned front block 24 of the rigid frame structure. The ways 13, 14 permit the carriers 9 to swivel back and forth about an axis which is parallel to the cylinder 16 so that the front sole plate 6 can be pivoted from the normal or neutral solid-line position of FIG. 2 (when the mine floor is smooth and substantially horizontal) to either one of two end positions one of which is indicated in FIG. 2 by phantom lines. In this way, the sole plate 6 can move into substantial surfacc-to-surface engagement with a very uneven or rough mine floor, either by pivoting in response to displacement of front carriers 9 along the guide means 13, 14 and/or due to pivotal movement about the common axis of the pivots 12. Stops 15 limit the extent of movement of carriers 9 along the guide means 13 and 14. The axis about which the carriers 9 can swing back and forth can be said to coincide or to 'be close to the longitudinal axis of the frame member 3. Since the carriers 9 are of arcuate shape, they cannot interfere with the operation of the shifting cylinder 16.

When the props 2a, 2b are shortened to move the caps 1 away from the mine roof, the sole plate 6 is held by several elastic coupling units 8 each of which may constitute a hydraulic or pneumatic shock absorber or a spring-loaded cylinder and piston assembly. In the illustrated embodiment, the coupling units 8 are assumed to include cylinders with spring-loaded pistons and their upper ends are attached to the front block 24, as at 11. The lower ends of the coupling units 8 are provided with eyes and are pivotably secured to the carriers 9 by bolts 10 or the like. These coupling units can yield when the sole plate 6 rests on an inclined (forwardly or laterally sloping) mine floor but tend to maintain the carriers 9 in a central or neutral position in which the sole plate 6 is located in a substantially horizontal plane. The parts 8, 9, 10, 11, 12, 13, 14, 23 together constitute a connector assembly between the frame structure 3, 22, 24 and the front sole plate 6.

The front props 2a are connected with the front block 24 by Way of sleeves 4 so that they have at least some freedom of vertical movement. The rear props 2b also extend through sleeves 4 carried by the rear block 24. Each prop is pivotably supported on the corresponding sole plate by a ball joint. The rear carrier means is preferably integral with the rear sole plate 5. This sole plate 5 is mounted on the frame member 3 (behind the cylinder 16) by way of a spherical joint 18 (FIG. 3) or an analogous universal joint.

The mine roof support further comprises two plate-like links 20 which are disposed between the sole plates 5, 6 at the opposite sides of the frame member 3 and are articulately connected to the sole plates by hinges 21 having pintles which are parallel to the pivots 12. In this way, the sole plates 5, 6 are movable relative to each other to follow the outline-of an uneven mine floor.

The carriers 9 or similarly mounted carriers can be used with advantage in mine roof supports wherein only one front pit prop is provided. In such apparatus, each carrier is preferably connected with at least one elastic coupling unit which is mounted on the rigid frame structure.

The front carriers 9 enable the front sole plate 6 to assume a practically unlimited number of positions and to thus closely follow the outline of an uneven mine floor. Moreover, the carriers 9 enable the front props 2a to remain substantially vertical in each angular position of the front sole plate 6 so that the parts 2a, 2a, 6 invariably constitute three sides of a parallelogram two sides of which, namely, the props 2a, 2a, are parallel to each other and the third side of which (the sole plate 6) may but need not be normal to such parallel sides. Universal adjustability of sole plates is particularly important in composite mine roof supports which are assembled of individual supports because the props of individual supports are suspended on their caps and the direction of props cannot follow the direction of sole plates. Thus, all unevennesses of the mine floor, particularly the downward slope toward the interior of an underground excavation, must be compensated for by the sole plate alone.

The elastic coupling units 8 can be omitted if the props of each group are connected to each other in such a way that they are held against excessive swaying and that they also prevent excessive swaying of sole plates when the caps are disengaged from the mine roof and while the apparatus moves toward the mine face. However, and when the props are mounted in a manner as shown in the drawing, the coupling units 8 constitute a desirable feature of the mine roof support because they invariably prevent swaying of props and of sole plates during movement of the apparatus toward the mine face. The carriers 9, the props 2a and the sole plate 6 are assembled with each other in such a way that they cannot and do not interfere with operation of the cylinder 16.

It is further possible to employ a single carrier 9 for each group of props. However, we prefer at this time to employ pairs of carriers because they contribute to rig idity, reliability and safety of the apparatus. The carriers 9 may consist of flat metallic sheet stock and are of substantially semicircular shape (see FIG. 2). Of course, the mounting of the rear sole plate can be identical with that of the front sole plate 6.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

We claim:

1. In a mine roof support which is movable in an underground excavation along the mine floor toward the mine face, a combination comprising a plurality of substantially upright pit prop means located one behind the other as considered in the direction of movement toward the mine face; a sole plate articulately supporting the lower portion of each prop means; a rigid frame structure movably engaging with said prop means; and a plurality of connector means securing said sole plates to said frame structure, at least one of said connector means comprising carrier means coupled with the respective sole plate and guide means provided on said frame structure for said carrier means to permit at least some movement of said carrier means with reference to the frame structure.

2. A combination as defined in claim 1, further comprising at least one elastic coupling unit connecting said carrier means with said frame structure.

3. A combination as defined in claim 1, wherein each of said prop means comprises a pair of transversely aligned props disposed at the opposite sides of said frame structure and each having a lower end portion articulately coupled to the respective sole plate, said carrier means comprising a pair of parallel carriers rigidly connected to each other and located in planes extending transversely of the direction of movement of the mine roof support toward the mine face.

4. A combination as defined in claim 1, wherein each of said prop means comprises a pair of transversely aligned props located at the opposite sides of said frame structure and each having a lower portion articulately mounted on the respective sole plate, said carrier means having end portions located at the opposite sides of said frame structure and said one connector means further comprising pivot members articulately connecting the end portions of said carrier means to the respective sole plate so that the latter is pivotable with reference to said carrier means about an axis extending transversely of the direction of movement of the mine roof support toward the mine face.

5. A combination as defined in claim 1, wherein said carrier means comprises at least one arcuate carrier of fiat metal stock and wherein said guide means comprises ways provided on said frame structure to permit movements of said carrier back and forth about an axis which is substantially parallel to the direction of movement of the mine roof support toward the mine face.

6. A combination as defined in claim 1, wherein said one connector means further comprises several elastic coupling units each secured to said frame structure and to said carrier means and arranged to bias said carrier means and the corresponding sole plate to a predetermined position with reference to said frame structure.

7. A combination as defined in claim 6, wherein each of said coupling units comprises a fluid-operated cylinder and piston assembly.

8. A combination as defined in claim 6, wherein each of said coupling units comprises a spring-loaded cylinder and piston assembly.

9. A combination as defined in claim 1, wherein another of said connector means comprises carrier means which is integral with the respective sole plate.

10. A combination as defined in claim 9, wherein said other connector means further comprises a universal joint connecting the respective sole plate to said frame structure.

11. A combination as defined in claim 1, wherein each of said prop means comprises a pair of transversely aligned props located at the opposite sides of said frame structure, said frame structure extending lengthwise between said pairs of props in the direction of movement of the support toward the mine face and said carrier means comprising a pair of arcuate carriers located in parallel vertical planes extending at right angles to said frame structure and rigid with each other, said guide means comprising arcuate ways for said carrier provided in said frame structure and permitting said carrier to move back and forth about an axis located between said pairs of props and extending in substantial parallelism with the direction of movement of the mine roof support toward the mine face, each of said carriers being articulately coupled to the respective sole plate.

12. A combination as defined in claim 11, wherein said last mentioned sole plate is the front sole plate of the mine roof support, the connector means for the rear sole plate of the mine roof support including a universal joint between such sole plate and said frame structure.

References Cited UNITED STATES PATENTS 3,113,661 12/1963 Linke et al. 61-45 3,201,943 8/ 1965 Wilkenloh et al. 61-45 3,218,812 11/1965 Wilkenloh 61-45 3,302,411 2/1967 Wilkenloh et al. 248-357 X 3,324,664 6/1967 Allen 61-45 3,328,967 7/ 1967 Wilkenloh 61-45 DENNIS L. TAYLOR, Primary Examiner US. Cl. X.R. 248-357 

